That’s because in each case, it was their last baby. Women can get pregnant up to age 45 or even 50 if they’ve already had babies. But there are women trying to have their very first babies at advanced ages, and that’s different.
Another problem, as I see it, is all the Hollywood celebrities having babies in their 40s, without mentioning that they used egg donors to do it. This gives ordinary women the impression that they have plenty of time and they, too, can wait till their 40s to be moms.
My mother and father tried to have children for twenty years with no success. My father went to a doctor and they found no issues with him, so they assumed my mother was infertile and went on about life. Then, out of the blue, she got pregnant at age 41, and here I am.